Unions representing more than 36,000 Verizon landline phone and cable workers are threatening a strike starting Wednesday morning if the company doesn't agree to a new contract.

The unions, the Communications Workers of America and the International Brotherhood of Electrical Workers, say Verizon wants to freeze pensions, make layoffs easier and rely more on contract workers.

Verizon says there are health care issues that need to be addressed for both retirees and workers as medical costs have grown, and it wants "greater flexibility" to manage its employees.

The latest contract had expired last August. Both sides say negotiations have been unsuccessful.

"It's been stressful because everyone wants to settle the contract," said Sherrie Lane, a 17-year Verizon employee who handles government and federal accounts.

For her, the biggest issues in the ongoing contract negotiations are healthcare costs and job security.

"That's the first thing. Then, on top of that, we don't want our jobs shipped overseas because they can ship them overseas and pay them next to nothing," Lane said.

Edward Mooney, the International Vice President for the Communications Workers of America District 213, and himself a Verizon employee, says pension and healthcare costs have been on the table during talks. However, he sees the outsourcing of jobs, such as those in the call centers, as the top issue yet to be resolved.

"Right now they want to contract the work of our call center to the tune of 50 percent of the workforce going to out-of-state contractors, or overseas contractors," Mooney said.

In a statement, Verizon's chief administrative officer said, "We've tried to work with union leaders to reach a deal. Verizon has been moving the bargaining process forward, but now union leaders would rather make strike threats than constructively engage at the bargaining table."

"We have good middle class jobs, but we're trying to keep them that way," said Mooney.

Verizon says it has trained thousands of non-union employees to fill in if the strike takes place in nine Eastern states and Washington, D.C. The company had 178,000 employees as of December.